X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FMonoid.hs;h=c51c4ca4bb0a90a25d798d10be388090c3e9a5c5;hb=2e317d707ce3512be60ada74a22119cd0a054ca1;hp=052472721ebb931dbec7bd476abae0f2775a9e41;hpb=dbf490ac992de84156826d846b25ecfbc4346744;p=ghc-base.git

diff --git a/Data/Monoid.hs b/Data/Monoid.hs
index 0524727..c51c4ca 100644
--- a/Data/Monoid.hs
+++ b/Data/Monoid.hs
@@ -20,21 +20,15 @@
 
 module Data.Monoid (
  	Monoid(..),
-	Endo(..),
 	Dual(..),
+	Endo(..),
+	All(..),
+	Any(..),
 	Sum(..),
 	Product(..)
   ) where
 
 import Prelude
-import Data.Map ( Map )
-import qualified Data.Map as Map hiding ( Map )
-import Data.IntMap ( IntMap )
-import qualified Data.IntMap as IntMap hiding ( IntMap )
-import Data.Set ( Set )
-import qualified Data.Set as Set hiding ( Set )
-import Data.IntSet ( IntSet )
-import qualified Data.IntSet as IntSet hiding ( IntSet )
 
 -- ---------------------------------------------------------------------------
 -- | The monoid class.
@@ -101,6 +95,14 @@ instance Monoid Ordering where
 	EQ `mappend` y = y
 	GT `mappend` _ = GT
 
+-- | The dual of a monoid, obtained by swapping the arguments of 'mappend'.
+newtype Dual a = Dual { getDual :: a }
+	deriving (Eq, Ord, Read, Show, Bounded)
+
+instance Monoid a => Monoid (Dual a) where
+	mempty = Dual mempty
+	Dual x `mappend` Dual y = Dual (y `mappend` x)
+
 -- | The monoid of endomorphisms under composition.
 newtype Endo a = Endo { appEndo :: a -> a }
 
@@ -108,15 +110,25 @@ instance Monoid (Endo a) where
 	mempty = Endo id
 	Endo f `mappend` Endo g = Endo (f . g)
 
--- | The dual of a monoid, obtained by swapping the arguments of 'mappend'.
-newtype Dual a = Dual { getDual :: a }
+-- | Boolean monoid under conjunction.
+newtype All = All { getAll :: Bool }
+	deriving (Eq, Ord, Read, Show, Bounded)
 
-instance Monoid a => Monoid (Dual a) where
-	mempty = Dual mempty
-	Dual x `mappend` Dual y = Dual (y `mappend` x)
+instance Monoid All where
+	mempty = All True
+	All x `mappend` All y = All (x && y)
+
+-- | Boolean monoid under disjunction.
+newtype Any = Any { getAny :: Bool }
+	deriving (Eq, Ord, Read, Show, Bounded)
+
+instance Monoid Any where
+	mempty = Any False
+	Any x `mappend` Any y = Any (x || y)
 
 -- | Monoid under addition.
 newtype Sum a = Sum { getSum :: a }
+	deriving (Eq, Ord, Read, Show, Bounded)
 
 instance Num a => Monoid (Sum a) where
 	mempty = Sum 0
@@ -124,27 +136,8 @@ instance Num a => Monoid (Sum a) where
 
 -- | Monoid under multiplication.
 newtype Product a = Product { getProduct :: a }
+	deriving (Eq, Ord, Read, Show, Bounded)
 
 instance Num a => Monoid (Product a) where
 	mempty = Product 1
 	Product x `mappend` Product y = Product (x * y)
-
-instance (Ord k) => Monoid (Map k v) where
-    mempty  = Map.empty
-    mappend = Map.union
-    mconcat = Map.unions
-
-instance Ord a => Monoid (IntMap a) where
-    mempty  = IntMap.empty
-    mappend = IntMap.union
-    mconcat = IntMap.unions
-
-instance Ord a => Monoid (Set a) where
-    mempty  = Set.empty
-    mappend = Set.union
-    mconcat = Set.unions
-
-instance Monoid IntSet where
-    mempty  = IntSet.empty
-    mappend = IntSet.union
-    mconcat = IntSet.unions